There is no question that it is not legal to download a game you did not purchase, my post was purely focused on the morality of it. As someone who works in the software industry I am completely against pirating, as downloading something you could have purchased is morally wrong (be it games, movies, music, what have you...). But when there is no way of legally purchasing a game (aside from ebay, which only benefits the seller), I think that line starts to get pretty fuzzy.
But I do believe in another decade or so we could potentially start losing these games if they don't start either re-selling them or re-classifying them as abandonware... Hard drives crash, floppy disks stop working, even burned cd's have a limited shelf life. To everyone who has a legal copy, preserve those backups! And to everyone like myself who purchased the game 17 years ago, but the disks have been lost over the years: Too bad! Because the only way to reliably get another copy is to pirate it.
As an aside, LucasArts could solve this by simply selling downloadable copies of all its old games for $10 a pop. I'd buy them...